Good to knowOne result rarely tells the whole story. Your provider looks at your results together with your symptoms, exam, and other tests.
What the test is
Many healthy people have HLA-B27, so a positive test alone doesn't mean disease.
Why it's done
- Long-lasting low back pain and stiffness, especially in younger adults
- Eye inflammation (uveitis) or reactive arthritis
Getting ready and what happens
- No preparation is needed.
How the test is done
- A health worker cleans the skin, puts a band around your arm, and draws blood from a vein with a small needle. It takes a few minutes.
What the results mean
Positive
With matching symptoms and imaging, supports ankylosing spondylitis.
Questions to ask your provider
- What do my results mean for me?
- Do I need to repeat this test or have other tests?
Risks
A blood draw is very safe. You may have slight pain or a small bruise where the needle went in.
Related conditions
Related medicines
Related tests
Sources
Last updated 2026-11-13.